Disc cartridge and disc recording and/or reproducing apparatus

ABSTRACT

A disc cartridge provided with: a plurality of trays, each of which can place a disc; and a case where those trays can be taken in and out of an opening, wherein an operating unit is disposed in each of the trays, a guide rail is disposed in either one of the trays and the case in a direction in which the trays are taken in and out of the case, and a fitting unit is disposed in the other of the trays and the case so as to be fit in the guide rail in order to guide the trays along this guide rail, and when the trays are taken in and out of the case, they can be smoothly taken in and out in such a way that the trays are not caught by the case, and a disc recording and/or reproducing apparatus having such a disc cartridge.

CROSS REFERENCES TO RELATED APPLICATIONS

[0001] The present document is based on Japanese Priority Document JP2000-350520, filed in the Japanese Patent Office on Nov. 17, 2000, theentire contents of which being incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to: a disc cartridge provided witha plurality of trays each holding a disc, and a cartridge case assembledso as to enable those trays to be taken in and out, in which anoperating unit disposed in the tray is drawn or pressed to thereby takethe tray in and out; and a disc recording and/or reproducing apparatus(hereafter, referred to as a disc auto-changer) for recording on and/orreproducing from the disc on the tray by using the disc cartridge.

[0004] 2. Description of the Related Art

[0005] A disc cartridge shown in FIG. 32 is known as the above-mentioneddisc cartridge (also referred to as a disc magazine). The disc cartridge201 is provided with a plurality of trays 203 each holding a discoidrecording medium (hereafter, referred to as a disc) 202; and a cartridgecase 204 assembled so as to enable those trays 203 to be taken in andout, in which an operating unit 205 (hereafter, referred to as a hook)disposed in the tray 203 is drawn or pressed to thereby take the tray203 in and out of the cartridge case 204.

[0006] The disc cartridge 201 is used in such a way that the respectivetrays 203 are taken out of the cartridge case 204, and the respectivediscs 202 are placed thereon. The disc cartridge 201 is loaded into adisc auto-changer (not shown in FIG. 23) in a condition that the trays203 are returned back to the case 204.

[0007] As shown in FIG. 33, the disc auto-changer 301 is provided with:a cartridge loader 302 for loading the disc cartridge 201; an elevatingunit, namely, an elevator 303 arranged opposite to an opening of thecartridge loader 302; and an elevating control mechanism 304 forvertically elevating the elevator 303 along one side of the disccartridge 201.

[0008] After the elevating control mechanism 304 moves the elevator 303to a position corresponding to a tray 203 on which a desired disc 202 isplaced, a loading mechanism 305 disposed in the elevator 303 pulls thetray 203 into the elevator 303. Then, as shown in FIG. 34B, the disc 202on the tray 203 is placed on a turn table 306, and chucked by a chuckingplate 307. After that, a disc recording and/or reproducing unit composedof an optical pickup and the like mounted on the elevator 303 records onand/or reproduces from the disc.

[0009] By the way, in the case of the disc cartridge 201 and the discauto-changer 301, as shown in FIG. 35, left and right sides 204 a, 204 bof the cartridge case 204 and left and right sides 303 a, 303 b of theelevator 303 serve as guide planes of the tray 203. The tray 203 is slidwhile it is guided by those guide planes. This results in the followingproblems.

[0010] (1) If a moment in a direction indicated by an arrow M (adirection in which the tray is inclined to a direction A where it istaken in and out) is applied in pulling the hook 205 of the tray 203,the side 203 a of the tray 203 is pushed against the side 204 a of thecartridge case 204. Thus, a smooth slide of the tray 203 is impeded. Inthe worst case, the tray 203 is caught by the side 204 a, and it isstopped.

[0011] (2) Since a distance L between the guide planes is long, adimensional tolerance between the guide planes is large. Thus, in orderto attain an excellent guide effect, management of components isdifficult.

SUMMARY OF THE INVENTION

[0012] The present invention is proposed in view of the above-mentionedcircumstances and is to smoothly slide the tray even if a moment in atray rotation direction is applied to the hook of the tray, and easilycarry out the dimensional management of the parts and the like.

[0013] According to the present invention, since a slide guide isdisposed at a position aligned in substantial series with a hook of atray with respect to a direction, in which the tray is taken in and out,in a disc cartridge and an elevator, even if a moment in a trayinclination direction is applied to the hook in drawing the hook or inother cases, an inclination of the tray can be minimized to smoothlyslide the tray.

[0014] In the disc cartridge according to the present invention, thefitting between the guide rail disposed in either of the tray or thecase and the fitting unit disposed in the other tray or case enables thetray to be smoothly taken in and out. In addition, the slide guide isdisposed in substantial series with the direction, in which the tray istaken in and out, with respect to the operating unit (hook) of the tray.Thus, even if a moment in the tray inclination direction is applied tothe operating unit when the tray is taken in and out, the inclination ofthe tray can be minimized to smoothly slide the tray. Also, as comparedwith the conventional case in which the slide of the tray is guidedbetween the left and right sides of the cartridge case, the width of theguide plane can be reduced to thereby make a management of a part sizeand the like easier. Furthermore, in the disc cartridge according to thepresent invention, the slide guide is composed of the grooved concaveportion on the bottom surface of the tray and the ligulate convexportion on the cartridge case side. Thus, the structure of the slideguide is simple. Also, when the tray and the cartridge case are moldedfrom plastic, the concave portion and the convex portion can be formedintegrally with them. In addition, the divergently tapered convexportion insertion guide (tapered surface) is disposed at the end of thegrooved concave portion. Thus, due to the guide, the convex portion canbe inserted into the grooved concave portion easily and surely.

[0015] In the disc recording and/or reproducing apparatus according tothe present invention, the tray can be smoothly slid by guiding theslide of the tray not only in the cartridge case but also in theelevator. When the tray is pulled out of the disc cartridge, theligulate convex portion serving as the slide guide formed on theelevator side is introduced into the grooved concave portion formed onthe bottom surface of the tray. Accordingly, the convex portion guidesthe slide of the tray.

[0016] Furthermore, the disc recording and/or reproducing apparatusaccording to the present invention, the divergently tapered convexportion insertion guide formed at the end of the grooved concave portionformed on the bottom surface of the tray enables the ligulate convexportion to be inserted into the grooved concave portion easily andsurely. In addition, when the trays are pulled into the elevator by thepredetermined amount, the ligulate convex portion serving as the slideguide formed on the elevator side is put in the notch hole made in thesubstantial center of the grooved concave portion. Accordingly, the traycan be lowered correspondingly to it. Thus, after the disc supported onthe tray is placed on the disc table, the tray is lowered, which leadsto the non-contact state between the disc and the tray. Then, the disccan be rotated.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and other objects, features and advantages of thepresent invention will become more apparent from the followingdescription of the presently preferred exemplary embodiments of theinvention taken in conjunction with the accompanying drawings, in which:

[0018]FIG. 1 is a perspective view of a disc auto-changer of the presentinvention;

[0019]FIG. 2 is a perspective view of a disc cartridge;

[0020]FIG. 3 is a plan view of a disc tray when it is seen from a bottomside of the disc tray;

[0021]FIG. 4 is a front view of the disc cartridge;

[0022]FIG. 5 is a sectional view taken on a line V-V after the trays aretaken out;

[0023]FIG. 6 is a sectional view taken on the line V-V in a conditionthat the trays are accommodated;

[0024]FIG. 7 is a sectional view taken on a line VII-VII of a mainportion of FIG. 6;

[0025]FIG. 8 is a sectional view taken on a line VIII-VIII of the mainportion of FIG. 6;

[0026]FIG. 9 is a sectional view taken on a line IX-IX of the mainportion of FIG. 6;

[0027]FIG. 10 is a plan view of a main portion of the disc cartridge ina condition that the tray is pulled out;

[0028]FIG. 11 is a sectional view taken on a line XI-XI of a mainportion of FIG. 10;

[0029]FIG. 12 is a sectional view taken on a line XII-XII of the mainportion of FIG. 10;

[0030]FIG. 13 is a sectional view taken on a line XIII-XIII of the mainportion of FIG. 10;

[0031]FIG. 14 is a perspective view of an elevator;

[0032]FIG. 15 is a sectional view of a main portion of the elevator;

[0033]FIG. 16 is a front view of the main portion of the elevator;

[0034]FIG. 17A is a plan view of an upper block of the elevator;

[0035]FIG. 17B is a plan view of a lower block of the elevator;

[0036]FIG. 18 is an exploded perspective view of an elevating controlmechanism;

[0037]FIG. 19 is a side view of the disc auto-changer in a conditionthat the elevator is raised to a position corresponding to a tray on atop stage;

[0038]FIG. 20 is a side view of the disc auto-changer in a conditionthat the elevator is lowered to a position corresponding to a tray on abottom stage;

[0039]FIG. 21 is a side view of the disc auto-changer in a conditionthat the elevator is located at a waiting position;

[0040]FIG. 22 is a plan view of a loading mechanism;

[0041]FIG. 23 is an exploded perspective view of the loading mechanism;

[0042]FIG. 24 is a sectional view of the loading mechanism taken on aline XXIV-XXIV of FIG. 22;

[0043]FIG. 25 is a perspective view of the loading mechanism in acondition that the tray is pulled into a side of the elevator;

[0044]FIG. 26 is a plan view of a disc chucking mechanism;

[0045]FIG. 27 is a perspective view of the disc chucking mechanism;

[0046]FIG. 28 is a plan view showing a state of chucking a disc;

[0047]FIG. 29 is a front view showing the state of chucking the disc;

[0048]FIG. 30 is a plan view showing a state where chucking of a disc isreleased;

[0049]FIG. 31 is a front view of the chucking release state;

[0050]FIG. 32 is a perspective view of a conventional disc cartridge;

[0051]FIG. 33 is a perspective view of a conventional disc auto-changer;

[0052]FIG. 34A is a front view of a disc chucking mechanism showing astate of chucking release;

[0053]FIG. 34B is a front view of the disc chucking mechanism showing astate of chucking a disc; and

[0054]FIG. 35 is an explanation view showing a problem of theconventional disc cartridge.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0055] A disc cartridge and a disc recording and/or reproducingapparatus according to the present invention will be described below byusing a disc auto-changer and a disc cartridge used therein as anexample. This description will be divided into respective items of: (1)an explanation of an outline of the disc auto-changer; (2) anexplanation of the disc cartridge; (3) an explanation of an elevator;(4) an explanation of an elevating control mechanism; (5) an explanationof a loading mechanism; (6) an explanation of a disc chucking mechanism;(7) an explanation of an entire operation of the disc auto-changer; and(8) an explanation of another embodiment of the elevating controlmechanism. Then, the divided items are described in the above-mentionedorder.

[0056] (1) Explanation of Outline of Disc Auto-Changer

[0057]FIG. 1 is a perspective view of a disc auto-changer 1. The discauto-changer 1 is provided with: a disc cartridge 4 having a pluralityof disc placing trays 11 to be loaded into a cartridge accommodatingunit 3 of a mechanical chassis 2; an elevating unit (hereafter, referredto as an elevator) 5 arranged on a side of the cartridge accommodatingunit 3; an elevating control mechanism 6 for elevating the elevator 5along an opening 36 of the disc cartridge 4 loaded in the cartridgeaccommodating unit 3; a loading mechanism 7 (refer to FIG. 23) forreceiving and sending a tray between the disc cartridge 4 and theelevator 5; and a disc chucking mechanism 8 (refer to FIG. 14) forchucking the disc on the tray 11, which is fed to a side of the elevator5 by the loading mechanism 7, onto a disc table. The elevator 5 israised and lowered to a position of a desired tray 11 of the disccartridge 4. The desired tray 11 is fed to the side of the elevator 5 bythe loading mechanism 7. After that, a disc D placed on the tray 11 ischucked onto the disc table by the disc chucking mechanism 8. In thisway, the disc recording and/or reproducing operation is carried out.

[0058] (2) Explanation of Disc Cartridge

[0059]FIG. 2 is a perspective view of the disc cartridge 4. The disccartridge 4 has a plurality of trays 11 on which discs D are placed, anda case 12 assembled so as to enable those trays 11 to be pulled out.

[0060] The tray 11 has a disc positioning concave portion 13 so as toplace the disc D in an engaged state. From a center of the concaveportion 13 to one side portion, it has a notch 14 for disc tableintroduction and a notch 15 for pickup movement. Also, an operating unit16 (hereafter, referred to as a hook) in which a tray fitting unit(hereafter, referred to as a hook fitting unit) 91 of thelater-described loading mechanism 7 is fit is installed in one side of afront end (pulled out end) side of the tray 11.

[0061] A top surface of the hook 16 of each of the trays 11 serves as anaddress indicator 48 for indicating the number of the tray at which thetray is positioned from the uppermost tray (or from the lowermost tray).A serial number from 1 to n in order starting from the uppermost tray isindicated on the address indicator 48.

[0062] Also, an address indicator 49 for indicating the number of thattray is installed even at a position corresponding to each tray from theuppermost tray to the lowermost tray on one side of the case 12. Aserial number from 1 to n is given to the address indicator 49,similarly to the case of the above-mentioned tray.

[0063]FIG. 3 is a plan view of the tray 11 when it is viewed from itsturned over direction. The tray 11 has, on left and right sides of arear thereof, first and second supported members 17, 18 supported by apair of first and second tray supporters 42, 43 in a form of a rack,which are disposed in the case 12 described below.

[0064] A slide guide 9 (refer to FIG. 4) for guiding a slide of the trayis disposed between the second supported member 18 and the second traysupporter 43 for supporting it. The slide guide 9 is composed of: aguide rail disposed on a bottom surface of the second supported member18 of the tray 11, namely, a long grooved concave portion 19; and afitting unit formed on a top surface of the second tray supporter 43 ofthe case 12, namely, a ligulate convex portion (hereafter, referred toas a first guide protrusion) 46. As shown in FIG. 3, the long groovedconcave portion 19 is formed near the hook 16. In particular, it isdesired to be formed on the substantially same line as the hook 16, withrespect to a direction M-M′ in which the tray is taken in and out, andalso near the hook 16, such as this embodiment.

[0065] The long grooved concave portion 19 has a divergently taperedprotrusion insertion guide 20 at an end on a side of the hook 16, andhas a first hole 21 at a center and a second hole 22 at the other end.Also, the second supported member 18 has a downwardly slant plane 23 ona side of the second hole 22, a first dent portion 24 connected to theslant plane 23, and a first stopper 25 connected to the first dentportion 24.

[0066] The first supported member 17 also has a downwardly slant plane26, a second dent portion 27 connected to the slant plane 26, and asecond stopper 28 connected to the second dent portion 27, similarly tothe second supported member 18.

[0067] As shown in FIG. 2, the case 12 is constituted in a form of acompressed box by a top surface plate 31, a bottom surface plate 32, aleft side surface plate 33, a right side surface plate 34 and a rearsurface plate 35 so that the trays 11 are taken in and out of an opening36 of a front edge.

[0068] The case 12 is designed such that one side of the opening 36 iscut away to accordingly exhibit a so-called rounded-off condition, andthe hooks 16 of the trays 11 are exposed to external portion of the case12 from the rounded-off portion.

[0069]FIG. 4 is a front view of the disc cartridge 4. The case 12 has aplurality of disc accommodating units 41 for accommodating the trays 11in such a way that they can be pulled in and out. The disc accommodatingunit 41 is configured by disposing the pair of first and second traysupporters 42, 43 in the form of the shelf at positions opposite to eachother on inner surfaces of the left and right side surface plates 33,34.

[0070]FIG. 5 is a sectional view taken on a line V-V after the trays 11of FIG. 4 are taken out. The first and second tray supporters 42, 43horizontally support the first and second supported members 17, 18 ofthe tray 11, as mentioned above.

[0071] The first tray supporter 42 has a first notch 44 close to thefront end (opening 36) rather than a center of a longitudinal direction.Also, the second tray supporter 43 has a second notch 45 at a positionopposite to the first notch 44, and also has the first guide protrusion(ligulate convex portion) 46 inserted into the long grooved concaveportion 19 formed on the bottom surface of the tray 11, on an inner sideof the front end side. The first guide protrusion 46 is formed at a sizein such a way that it can not be engaged with the first hole 21 made inthe center of the concave portion 19, and it is formed at a size in sucha way that it can be engaged with the second hole 22.

[0072]FIG. 6 is a sectional view (a sectional view taken on the line V-Vof FIG. 4) showing the condition that the tray 11 is accommodated in thecase 12. FIG. 7 is a sectional view taken on a line VII-VII of a mainportion of FIG. 6. FIG. 8 is a sectional view taken on a line VIII-VIIIof the main portion of FIG. 6. FIG. 9 is a sectional view taken on aline IX-XI of the main portion of FIG. 6. In the condition that the tray11 is accommodated in the case 12, the first and second supportedmembers 17, 18 of the tray 11 are in a condition that they are placed onthe first and second tray supporters 42, 43 of the case 12. Also, thefirst guide protrusion 46 formed on the second tray supporter 43 isengaged with the long grooved concave portion 19 formed on the tray 11.Accordingly, the slide guide 9 is configured as mentioned above.

[0073] If the tray 11 is drawn by placing a fingertip in the hook 16 ofthe tray 11 or by engaging the hook fitting unit 91 of thelater-described loading mechanism 7 or by using other manners from thestate shown in FIG. 6, the tray 11 is straightly pulled out of the case12 without any inclination to the left and right directions by the longgrooved concave portion 19 and the first guide protrusion 46.

[0074]FIG. 10 is a sectional view showing a condition when the trays 11corresponding to FIG. 6 are pulled out of the case 12 by a predeterminedamount. FIG. 11 is a sectional view taken on a line XI-XI of a mainportion of FIG. 10. FIG. 12 is a sectional view taken on a line XII-XIIof the main portion of FIG. 10. FIG. 13 is a sectional view taken on aline XIII-XIII of the main portion of FIG. 10. When the trays 11 arepulled out of the case 12 by a predetermined amount, the first andsecond stoppers 25, 28 of the tray 11 are introduced into the first andsecond notches 44, 45 formed on the first and second tray supporters 42,43 of the case 12, and the first and second tray supporters 42, 43located in a forward direction from the first and second notches 44, 45of the case 12 are introduced into the first and second dent portions24, 27 connected to the first and second stoppers 25, 28. Then, due tothe first and second tray supporters 42, 43, the tray 11 becomes in acondition where top surfaces of the first and second dent portions 24,27 are supported. Moreover, the guide protrusion 46 formed on the case12 is engaged with the second hole 22 made on the tray 11. Thus, thetray 11 becomes in a condition that its fall from the case 12 isprotected.

[0075] (3) Explanation of Elevator

[0076] The elevating unit, namely, the elevator 5 is arranged oppositeto the opening 36 of the disc cartridge 4, and is raised/lowered to adesired disc accommodating unit, namely, a position of the tray by usingthe elevating control mechanism 6. A disc placed on the tray pulled outof the disc cartridge by the loading mechanism 7 is chucked onto thedisc table by the disc chucking mechanism 8. Then, the disc recordingand/or reproducing operation is carried out by a recording and/orreproducing unit composed of an optical pickup and the like.

[0077]FIG. 14 is a perspective view of the elevator 5. FIG. 15 is asectional view taken on a main portion of FIG. 14. FIG. 16 is a frontview of the elevator 5. FIGS. 17A and 17B are plan views of an upperblock and a lower block, respectively, constituting the elevator 5.

[0078] As shown in FIGS. 14, 15, the elevator 5 is provided with: anupper block 51; a lower block 53 rotatably installed through a firstshaft 52 to the upper block 51; first and second lower block rotationoperating units 54, 55 slidably installed to both sides of the upperblock 51; and first and second link levers 56, 57 for linking the firstand second lower block rotation operating units 54, 55 to each other andmoving them in the same direction in synchronization with each other. Inthe first link lever 56, one end thereof is connected to the first lowerblock rotation operating unit 54 through a first pin 58. A centerportion thereof is rotatably attached to a lower surface of the upperblock 51 through a second pin 59. The other end is connected to one endof the second link lever 57 through a third pin (hereafter, referred toas a connecting pin) 60.

[0079] With regard to the second link lever 57, a center portion thereofis rotatably attached to a bottom surface of the upper block 51 througha fourth pin 61. The other end is connected to the second lower blockrotation operating unit 55 through a fifth pin 62.

[0080] If any one of the first and second lower block rotation operatingunits 54, 55 is slid, the other unit is also slid to the same directionthrough the first or second link levers 56, 57.

[0081] Each of the first and second lower block rotation operating units54, 55 has an inclined operation groove 63. A second shaft 64 disposedon the other end side (the end opposite to the first shaft 52) of thelower block 53 is inserted into the operation groove 63. As shown by asolid line in FIG. 14, in a condition that the second shaft 64 islocated on the lower end side of the inclined operation groove 63, afree end side of the lower block 53 is downwardly inclined with thefirst shaft 52 as a center, as shown in FIG. 15. After the insertion ofthe tray, the first and second lower block rotation operating units 54,55 are moved to a direction indicated by an arrow A, as shown by atwo-dot chain line in FIG. 14. Then, the second shaft 64 is located onan upper end side of the inclined operation groove 63. Accordingly, thelower block 53 is substantially horizontally lifted up and maintained.

[0082] As shown in FIG. 16, the upper block 51 has on left and rightsides thereof, a pair of tray supporters (hereafter, the tray supportersof this elevator 5 are referred to as third and fourth tray supporters)65, 66. The third and fourth tray supporters 65, 66 support the firstand second supported members 17, 18 on both the sides of the tray 11pulled out of the disc cartridge 4.

[0083] The third tray supporter 65 has a guide protrusion (hereafter,this guide protrusion of the elevator 5 is referred to as a second guideprotrusion) 67, which is inserted into the long grooved concave portion19 of the tray 11 pulled out of the disc cartridge 4 to then guide theoperation for pulling the tray 11 in.

[0084] When the tray 11 is pulled into the elevator 5 up to a maximum,the second guide protrusion 67 is engaged with the second hole 21 madein center of the long grooved concave portion 19 of the tray 11, asshown in FIG. 12. Accordingly, it is allowable to lower the tray 11 byapproximately 1 mm.

[0085] As shown in FIG. 17A, the upper block 51 includes the loadingmechanism 7 and the disc chucking mechanism 8. Also, as shown in FIG.17B, the lower block 53 includes a disc recording and/or reproducingunit provided with: a disc table 68; a disc rotation driving mechanismand optical pickup 69 composed of a spindle motor 70 for rotationallydriving this disc table 68; and an optical block composed of a carriage71 having the optical pickup 69 and the like. By the way, the carriage71 moves the optical pickup 69 along a guide shaft 72. Moreover, acarriage driving mechanism 73 drives the carriage 71. The carriagedriving mechanism 73 has a motor 74, a gear train 75 and a lead screw76. Since the motor 74 rotates the lead screw 76 through the gear train75, the carriage 71 is moved along the guide shaft 72. Accordingly, theoptical pickup 69 mounted on the carriage 71 is moved to a radiusdirection of a disc D chucked on the disc table 68.

[0086] As shown in FIG. 18, the elevator 5 has a first supported shaft77 on one side thereof, and has second and third supported shafts 78, 79on the other side. The elevator 5 is installed to a mechanical chassis10 in such a way that it can be vertically raised and lowered, byinserting the first supported shaft 77 into a first elevating guidegroove 10 b formed on a first side surface 10 a of the mechanicalchassis 10 and inserting the second and third supported shafts 78, 79into second and third elevating guide grooves 10 d, 10 e formed on asecond side surface 10 c of the mechanical chassis 10.

[0087] The elevator 5 is raised and lowered to the position of thedesired tray 11 of the disc cartridge 4 by the elevating controlmechanism 6 described below. Accordingly, the tray 11 is pulled out, andthe disc D is chucked onto the disc table 68. Then, the disc recordingand/or reproducing operation is carried out by the recording and/orreproducing unit composed of the optical pickup 69 and the like.

[0088] (4) Explanation of Elevating Control Mechanism

[0089] The elevating control mechanism raises and lowers the elevator 5to the position of the desired tray in the disc cartridge 4.

[0090]FIG. 18 is an exploded perspective view of the elevating controlmechanism 6. FIG. 19 is a side view of the elevating control mechanism 6in a condition that the elevator 5 is moved to a position correspondingto a tray on a top stage of the disc cartridge 4. FIG. 20 is a side viewof the elevating control mechanism 6 in a condition that the elevator 5is moved to a position corresponding to a tray on a bottom stage of thedisc cartridge 4. FIG. 21 is a side view of the elevating controlmechanism 6 in a condition that the elevator 5 is standing at a waitingposition.

[0091] As shown in FIG. 18, the elevating control mechanism 6 includes:a first elevating operation plate 81 to be slidably superimposed on anexternal surface of the first side surface 10 a of the mechanicalchassis 10; a second elevating operation plate 82 to be slidablysuperimposed on an external surface of the second side surface 10 c ofthe mechanical chassis 10; a link lever 83 for connecting the first andsecond elevating operation plates 81, 82 to each other; and an operationplate driving mechanism 84 for sliding the second elevating operationplate 82.

[0092] The first elevating operation plate 81 has a first operationgroove 85 for supporting the first supported shaft 77 of the elevator 5at an intersection with the first elevating guide groove 10 b formed onthe first side 10 a of the mechanical chassis 10.

[0093] The first operation groove 85 has an inclined groove 85 a forelevating an elevating operation, and a horizontal waiting groove 85 cconnected through a linkage groove 85 b to a lower end of the inclinedgroove 85 a for the elevating operation.

[0094] As shown in FIG. 19, the first elevating operation plate 81supports the elevator 5 at the position corresponding to the tray 11 onthe top stage of the disc cartridge 4, in a condition that the firstsupported shaft 77 is located at an upper end of the inclined groove 85a for the elevating operation.

[0095] As shown in FIG. 20, the first elevating operation plate 81supports the elevator 5 at the position corresponding to the tray 11 onthe bottom stage of the disc cartridge 4, in a condition that the firstsupported shaft 77 is located at a lower end of the inclined groove 85 afor the elevating operation. In this case, a lower end 5 a of theelevator 5 is in a condition that it protrudes from a lower end 10 f ofthe mechanical chassis 10.

[0096] As shown in FIG. 21, in a condition that the first supportedshaft 77 is located at the horizontal waiting groove 85 c, the firstelevating operation plate 81 together with the second elevatingoperation plate 82 described below is designed so as to raise theelevator 5 from the position corresponding to the tray 11 on the bottomstage to a position at which the lower end 5 a of the elevator 5 doesnot protrude from the lower end 10 f of the mechanical chassis 10 (aposition where the lower end 5 a of the elevator 5 is accommodated inthe mechanical chassis 10) and to keep it at the waiting state.

[0097] Also, as shown in FIG. 18, the second elevating operation plate82 has a second operation groove 86 for supporting the second supportedshaft 78 of the elevator 5 at an intersection with the second elevatingguide groove 10 d formed on the second side surface 10 c of themechanical chassis 10, and a third operation groove 87 for supportingthe third supported shaft 79 of the elevator 5 at an intersection withthe third elevating guide groove 10 e.

[0098] The second operation groove 86 has an inclined groove 86 a forthe elevating operation, and a horizontal waiting groove 86 c connectedthrough a linkage groove portion 86 b to a lower end of the groove 86 afor the elevating operation, similarly to the first operation groove 85.

[0099] The third operation groove 87 also has an inclined groove 87 afor the elevating operation, and a horizontal waiting groove 87 cconnected through a linkage groove 87 b to a lower end of the groove 87a for the elevating operation, similarly to the second operation groove86.

[0100] In a condition that the second and third supported shafts 78, 79of the elevator 5 are located at upper ends of the inclined grooves 86a, 87 a for the elevating operation of the second and third operationgrooves 86, 87, the second elevating operation plate 82 together withthe first elevating operation plate 81 is designed so as to support theelevator 5 at the position corresponding to the tray 11 on the top stageof the disc cartridge 4. In a condition that the second and thirdsupported shafts 78, 79 of the elevator 5 are located at lower ends ofthe grooves 86 a, 87 a for the elevating operation, it is designed so asto support the elevator 5 at the position corresponding to the tray 11on the bottom stage of the disc cartridge 4. And, in a condition thatthe second and third supported shafts 78, 79 of the elevator 5 arelocated at the horizontal waiting grooves 86 c, 87 c, it is designed soas to raise the elevator 5 from the position corresponding to the tray11 on the bottom stage to a position at which the lower end 5 a of theelevator 5 does not protrude from the lower end 10 f of the mechanicalchassis 10 (a position where the lower end 5 a of the elevator 5 isaccommodated in the mechanical chassis) and to keep it at the waitingstate.

[0101] The second and third operation grooves 86, 87 are formedoppositely to the first operation groove 85. Accordingly, the firstelevating operation plate 81 and the second elevating operation plate 82are slid to the directions opposite to each other to then raise andlower the elevator 5.

[0102] With regard to the link lever 83, a center portion thereof isrotatably attached to the mechanical chassis 10 through a shaft 83 a.One end thereof is linked to the first elevating operation plate 81through a first pin 83 b and a first long hole 83 c. The other end islinked to the second elevating operation plate 82 through a second pin83 d and a second long hole 83 e.

[0103] The link lever 83 is rotated with the shaft 83 a as a center ifthe first elevating operation plate 81 is slid in one direction by theoperation plate driving mechanism 84. Accordingly, the second elevatingoperation plate 82 is slid in an opposite direction in synchronizationwith the first elevating operation plate 81.

[0104] The elevating control mechanism 6 of the embodiment has theabove-mentioned configuration. As shown in FIG. 19, in a condition thatthe first elevating operation plate 81 is moved to the leftmostposition, the second elevating operation plate 82 becomes in a conditionthat it is moved to the rightmost position on the side of the secondside surface 10 c of the mechanical chassis 10. Then, the elevatingcontrol mechanism 6 supports the first supported shaft 77 of theelevator 5 at an upper end of the inclined groove 85 a for the elevatingoperation of the first operation groove 85 of the first elevatingoperation plate 81, and also supports the second and third supportedshafts 78, 79 of the second elevating operation plate 82, and furthersupports the elevator 5 at the position corresponding to the tray 11 onthe top stage of the disc cartridge 4.

[0105] When the first elevating operation plate 81 is moved from thestate shown in FIG. 19 to the right by a predetermined amount, thesecond elevating operation plate 82 is moved to the left insynchronization with that movement of the first elevating operationplate 81. Accordingly, for each movement of the predetermined amount,the elevator 5 is moved to a position corresponding to each of the trayson the second stage, the third stage . . . from the top of the disccartridge 4.

[0106] Then, as shown in FIG. 20, when the first supported shaft 77 ofthe elevator 5 is supported at the lower end of the inclined groove 85 afor the elevating operation of the first operation groove 85 of thefirst elevating operation plate 81, the second and third supportedshafts 78, 79 of the elevator 5 are supported at the lower ends of theinclined grooves 86 a, 87 a for the elevating operation of the secondand third operation grooves 86, 87 of the second elevating operationplate 82. Accordingly, the elevator 5 is supported at the positioncorresponding to the tray on the bottom stage.

[0107] When the first elevating operation plate 81 is further moved fromthe condition shown in FIG. 20 to the right by the predetermined amount,the second elevating operation plate 82 is also moved to the left insynchronization with that movement of the first elevating operationplate 81. The first, second and third supported shafts 77, 78, and 79are inserted into the waiting grooves 85 c, 86 c and 87 c of the first,second and third operation grooves 85, 86, and 87. Accordingly, thelower end 5 a of the elevator 5 is supported at a waiting position whichis at least located upper than the lower end 10 f of the mechanicalchassis 10.

[0108] (5) Explanation of Loading Mechanism

[0109] The loading mechanism 7 is the mechanism for feeding the tray(disc) from the disc cartridge 4 to the elevator 5, and feeding, namely,returning the tray from the elevator 5 to the disc cartridge 4.

[0110]FIG. 22 is a plan view of the loading mechanism 7. FIG. 23 is anexploded perspective view of the loading mechanism 7. FIG. 24 is asectional view taken on a line XXIV-XXIV of FIG. 22. FIG. 25 is aperspective view showing a condition that the tray is pulled in theelevator 5.

[0111] As shown in FIG. 22, the loading mechanism 7 has the hook fittingunit 91 to be fit in the hook 16 of the tray 11; a belt 92 for movingthe hook fitting unit 91 to a direction in which the tray is taken inand out; and a belt driving mechanism 93 for driving the belt 92. Thehook fitting unit 91 is arranged on a top side of the third traysupporter 65 of the upper block 51 of the elevator 5. The belt 92 andthe belt driving mechanism 93 are arranged on a bottom side of the thirdtray supporter 65.

[0112] As shown in FIG. 23, the hook fitting unit 91 has a coupling unit91 a to be coupled to the belt 92. The coupling unit 91 a protrudes to abottom side of the third tray supporter 65 through a guide hole 65 amade in the third tray supporter 65, and it is installed on the belt 92via a pin 91 b.

[0113] The belt 92 is configured to have no end, namely, it is endless.(Hereafter, the belt 92 is referred to as an endless belt). The endlessbelt 92 is hung on a first pulley 94 and a second pulley 95. When theendless belt 92 rotates, the hook fitting unit 91 moves to thedirection, in which the tray is taken in and out, along the guide hole65 a. A number of notch holes 92 a are made on the endless belt 92 at apredetermined interval in that rotational direction.

[0114] The belt driving mechanism 93 is provided with: a sprocket 100for driving the endless belt 92; a first gear 101 on the same shaft asthe sprocket 100; a second gear 102 engaged with the first gear 101; athird gear 103 engaged with the second gear 102; a fourth gear 104 onthe same shaft as the third gear 103, a fifth gear 105 engaged with thefourth gear 104; and a loading motor 106 for rotating the fifth gear105.

[0115] Protrusions 100 a to be fit in the notch holes 92 a of theendless belt 92 are formed on a circumference plane of the sprocket 100.

[0116] The first gear 101 is disposed on a bottom surface of thesprocket 100 having a spacer 107 therebetween. A notch 108 in a form ofcircular arc is formed in the spacer 107.

[0117] A non-tooth portion 109 is disposed on an upper half of thesecond gear 102. Also, a rib 110 in a form of circular arc, which isopposite to the notch 108 of the spacer 107, is disposed in a portioncorresponding to the non-tooth portion 109 on the top surface of thesecond gear 102. The first gear 101 is engaged with the upper half ofthe second gear 102 having the non-tooth portion 109. The third gear 103is designed to be engaged with both the upper half and the lower half ofthe second gear 102. A screw gear (helical gear) is used in the fourthgear 104, and a worm gear is used in the fifth gear 105.

[0118] As shown in FIG. 22, in a condition that the hook fitting unit 91is advanced to the closest position to a tray outlet/inlet side of theelevator 5, if the disc cartridge 4 is inserted into the cartridgeaccommodating unit 3 of the mechanical chassis 10 from a directionindicated by an arrow A, the hook 16 of the tray 11 is naturally fit inthe hook fitting unit 91.

[0119] If the motor 106 is rotated to one direction in this condition,the sprocket 100 is counterclockwise rotated through the fifth gear 105to the first gear 101, and the endless belt 92 is clockwise rotated.Accordingly, the tray 11 is pulled into the elevator 5 as shown in FIG.25. Then, if the tray 11 is pulled into a predetermined position, theengagement between the second gear 102 and the first gear 101 isreleased to thereby stop the rotations of the sprocket 100 and theendless belt 92.

[0120] As shown in FIG. 23, a sixth gear 111 for rotating the lowerblock 53 of the elevator 5 in linkage with the loading mechanism 7 isinstalled on the top surface of the second gear 102.

[0121] The sixth gear 111 has a non-tooth portion 111 a. The sixth gear111 is engaged with a rack 112 a of a rack member 112 which is installedto the lower end of the second lower block rotation operating unit 55 ofthe elevator 5. The rack member 112 has an inclined operation groove 63on one side. The second shaft 64 on one side of the lower block 53 ofthe elevator 5 is inserted into the operation groove 63. The rack member112 is installed to an installation portion 55 a of the lower end of thesecond lower block rotation operating unit 55 of the elevator 5.

[0122] As mentioned above, when the tray 11 is pulled in up to thepredetermined position to thereby release the engagement between thesecond gear 102 and the first gear 101, the sixth gear 111 and the rackmember 112 are engaged with each other. Then, the rack member 112 andthe second lower block rotation operating unit 55 are moved to the left(a direction indicated by an arrow A) of FIG. 23 to thereby push up thesecond shaft 64 to the upper end side of the inclined operation groove63. On the other hand, the movement of the second lower block rotationoperating unit 55 causes the first lower block rotation operating unit54 to be also moved to the same direction through the first and secondlink levers 56, 57. Accordingly, as shown in FIG. 27, the second shaft64 on the other side of the lower block 53 is pushed up to the upper endside of the inclined operation groove 63, similarly to the second lowerblock rotation operating unit 55. Then, the lower block 53 is upwardlyrotated to thereby place on the disc table 68 the disc D supported onthe tray 11.

[0123] Also, as mentioned above, if the loading motor 106 is reversiblyrotated from a condition that the lower block 53 is upwardly rotated,the rack member 112 and the second lower block rotation operating unit55 are moved oppositely to the direction when the tray is pulled in. Inlinkage with this movement, the first lower block rotation operatingunit 54 is also moved to the same direction, and the lower block 53 isdownwardly rotated, which results in a condition that the disc table 68is separated from the tray 11. Next, the second gear 102 and the firstgear 101 are engaged with each other, and the sprocket 100 and theendless belt 92 are rotated oppositely to the direction at the time whenthe tray is pulled in. Accordingly, the tray 11 is pushed back into thedisc cartridge 4 by the hook fitting unit 91.

[0124] (6) Explanation of Disc Chucking Mechanism

[0125] The disc chucking mechanism 8 is the mechanism for pushing thedisc against the disc table 68, and protecting the disc from slipping onthe disc table 68, and integrally rotating the disc table 68 and thedisc, and surely carrying out the disc recording and/or reproducingoperation.

[0126]FIG. 26 is a plan view showing a condition when the disc chuckingmechanism 8 is assembled on the top surface of the elevator 5. FIG. 27is a perspective view of the disc chucking mechanism 8. FIG. 28 is aplan view showing the chucking state. FIG. 29 is a front view of thechucking state. FIG. 30 is a plan view showing a chucking release state.FIG. 31 is a front view of the chucking release state.

[0127] The disc chucking mechanism 8 is provided with: a chucking plate121 for pressing the disc; a chucking plate supporter 122 for supportingthe chucking plate 121; and an operating unit 123 for pushing thechucking plate 121 against the disc through the chucking plate supporter132.

[0128] The chucking plate 121 is configured in a form of a circle havinga diameter substantially equal to that of the disc table 68. A centerportion thereof is supported by the chucking plate supporter 122 in acondition that a somewhat vertical motion is allowable by a shaft 131.

[0129] The chucking plate supporter 122 is made of a leaf springmaterial, and it is slenderly rectangular. First and second long holes132, 133 are made in one end and the other end of a longitudinaldirection, respectively. First and second protrusions 134, 135protruding toward a bottom side are formed on inner sides of the firstand second long holes 132, 133.

[0130] The chucking plate supporter 122 is installed on the top surfaceof the upper block 51 of the elevator 5 through first and second shafts136, 137 inserted into the first and second long holes 132, 133, so thatit can be moved in the longitudinal directions of the first and secondlong holes 132, 133.

[0131] As shown in FIG. 29, the chucking plate supporter 122 isdownwardly curved, and a spring force in a direction in which thechucking plate 121 is pushed against the disc table 68 is given to it.

[0132] As shown in FIG. 28, the operating unit 123 is provided with: abase 141; and first and second arms 142, 143 branched into two partsfrom a tip of the base 141.

[0133] The base 141 is provided with: first and second long slide guideholes 144, 145; and a long connecting pin reception hole 146 madebetween the first and second slide guide holes 144, 145.

[0134] The base 141 is installed on a top surface of the upper block 51of the elevator 5 through the first and second slide guide members 147,148 by using the first and second slide guide holes 144, 145 so that itcan be slid within a range of lengths of the first and second slideguide holes 144, 145. Also, the connecting pin 60 between the first linklever 56 and the second link lever 57 which are placed on the topsurface of the upper block 51 is loosely engaged with the connecting pinreception hole 146.

[0135] The first and second arms 142, 143 are provided with: chuckingplate supporter pushers 151 for abutting to the bottom surfaces of thefirst and second protrusions 134, 135, and then pushing up the first andsecond protrusions 134, 135 and the chucking plate supporter 122 againstits spring force, and further separating the chucking plate 121 from thedisc D on the disc table 68; and chucking plate supporter loweringpermitters 153 connected through falling gradient planes 152 to thepushers 151.

[0136] As shown in FIG. 28, when the operating unit 123 is slid to adirection indicated by an arrow A, the chucking plate supporter loweringpermitters 153 of the first and second arms 142, 143 are located on thebottom surfaces of the first and second protrusions 134, 135 of thechucking plate supporter 122. As shown in FIG. 29, the chucking platesupporter 122 is downwardly deformed by a spring force itself to therebylower the chucking plate 121 toward the side of the disc table 68.Accordingly, the disc D is sandwiched between the chucking plate 121 andthe disc table 68, which results in the chucking state. (At this time,the lower block 53 of the elevator 5 is upwardly rotated in linkage withthe operation of the operating unit 123, which leads to a raised stateof the disc table 68.)

[0137] Also, as shown in FIGS. 30, 31, when the operating unit 123 isslid to a direction indicated by an arrow B, the chucking plate pushers151 of the first and second arms 142, 143 are located on the bottomsurfaces of the first and second protrusions 134, 135 of the chuckingplate supporter 122. Accordingly, the chucking plate supporter 122 ispushed up against the spring force itself to thereby separate thechucking plate 121 from the disc of the disc table 68. (At this time,the lower block 53 of the elevator 5 is downwardly rotated in linkagewith the operation of the operating unit 123, which leads to a loweredstate of the disc table 68.)

[0138] The linkage operation between the operating unit 123 and thelower block 53 is carried out through the first and second link levers56, 57 disposed on the bottom surface of the upper block 51 of theelevator 5.

[0139] As shown in FIG. 27, when the tray 11 is loaded to thepredetermined position of the elevator 5 by the loading mechanism 7, thesecond lower block rotation operating unit 55 of the elevator 5 is movedto the direction indicated by the arrow A by the loading mechanism 7.(For further description, refer to the above item [(2) Explanation ofElevator]).

[0140] When the second lower block rotation operating unit 55 is slid tothe direction indicated by the arrow A, the second link lever 57 whoseone end is coupled through the fifth pin 62 to the second lower blockrotation operating unit 55 is counterclockwise rotated with the fourthpin 61 as a center. The first link lever 56 is clockwise rotated throughthe connecting pin 60 with the second pin 59 as a center. Also, thefirst lower block rotation operating unit 54 connected through the firstpin 58 to one end of the first link lever 56 is moved to the directionindicated by the arrow A. In short, the second lower block rotationoperating unit 55 and the first lower block rotation operating unit 54are slid to the direction indicated by the arrow A, in synchronizationwith each other. Thus, the second shaft 64 of the lower block 53 islocated on the upper end side of the inclined operation groove 63 formedin the lower portions of the first and second lower block rotationoperating units 54, 55, and the lower block 53 is clockwise rotated withthe first shaft 52 as a center. Accordingly, the disc table 68 israised.

[0141] As mentioned above, when the second link lever 57 iscounterclockwise rotated with the fourth pin 61 as the center, theoperating unit 123 is slid to the direction indicated by the arrow B,through the connecting pin 60 between the first and second link levers56, 57 and the connecting pin reception hole 146. Thus, the chuckingplate supporter lowering permitters 153 of the first and second arms142, 143 are located at the lower portions of the first and secondprotrusions 134, 135 of the chucking plate supporter 122. Hence, thechucking plate supporter 122 is deformed by its spring force. Thisdeformation causes the chucking plate 121 to push the disc D against thedisc table 68. Accordingly, the operation for chucking the disc D iscarried out.

[0142] Also, at a time of unloading the disc, the first and second lowerblock rotation operating units 54, 55 and the operating unit 123 areslid oppositely to the direction at the time of the loading. Thus, thechucking plate supporter 122 is pushed up to thereby raise the chuckingplate 121 to the chucking release position and downwardly rotate thelower block 53. Accordingly, the disc table 68 is separated from thedisc D and the tray 11.

[0143] (7) Explanation of Entire Disc Auto-Changer

[0144] When the respective discs D are placed on the trays 11 of thedisc cartridge 4, and the disc cartridge 4 is loaded to the cartridgeaccommodating unit 3, the hooks 16 of the trays 11 and the hook fittingunits 91 of the loading mechanism 7 disposed on the side of the elevator5 become in a condition that they can be engaged to each other.

[0145] Next, the elevating control mechanism 6 raises the elevator 5from the waiting position to a position corresponding to a tray 11 onwhich a desired disc is placed. Next, the loading mechanism 7 pulls thetray 11 on which the desired disc is placed, from the disc cartridge 4into the elevator 5.

[0146] When the tray 11 is pulled in up to the predetermined position,the loading mechanism 7 upwardly rotates the lower block 53 of theelevator 5, and then raises the disc table 68 included in the lowerblock 53, and further places the disc D of the tray 11 on the disc table68. In linkage with the rotational operation of the lower block 53, thedisc chucking mechanism 8 is actuated to thereby lower the chuckingplate 121, and chuck the disc D on the disc table 68, and also separatethe tray 11 from the bottom surface of the disc D. Then, the discrecording and/or reproducing operation is carried out under thatcondition.

[0147] After the end of the recording and/or reproducing operation, ifthe loading mechanism 7 is again actuated, the loading mechanism 7downwardly rotates the lower block 53 of the elevator 5. This downwardrotation makes the elevator 5 be separated from the disc D and the tray11. Also, in linkage with the rotation of the lower block 53, the discchucking mechanism 8 is actuated to thereby raise the chucking plate 121and accordingly release the chucking state of the disc.

[0148] Then, the continuous operation of the loading mechanism 7 causesthe tray 11 to be returned from the elevator 5 to the disc cartridge 4.When the tray 11 is perfectly returned to the disc cartridge 4, theelevating control mechanism 6 is again actuated to then return theelevator 5 to the waiting position.

[0149] (8) Explanation of Another Embodiment of Slide Guide

[0150] In the embodiment described above, there is illustrate the casewhen the grooved concave portions serving as the slide guide are formedon the bottom surface of the tray, and the ligulate convex portions tobe inserted into the grooved concave portions are formed on thecartridge case and the elevator side. However, on the contrary, thegrooved concave portions may be formed on the cartridge case and theelevator side, and the ligulate convex portions may be formed on thebottom surface of the tray.

[0151] Although the invention has been described in its preferred formwith a certain degree of particularity, obviously many changes andvariations are possible therein. It is therefore to be understood thatthe present invention may be practiced otherwise than as specificallydescribed herein without departing from the scope and the sprit thereof.

What is claimed is:
 1. A disc cartridge comprising a plurality of trays,each of which can place a disc thereon; and a case for accommodatingsaid plurality of trays in such a way that said trays can be taken inand out through an opening, wherein: each of said trays has anoperating; any one of said case and said trays has a guide rail disposedin a direction in which said trays are taken in and out of said case;and other one of said case and said trays has a fitting unit to be fitin said guide rail in order to guide said tray along this guide.
 2. Adisc cartridge comprising a plurality of trays, each of which can hold adisc; a case assembled so as to enable said trays to be taken in andout; and an operating unit disposed in each of said trays, which isdrawn or pressed to take said trays in and out of said case, wherein: aslide guide is disposed at a position in a direction, in which said trayis taken in and out, near said operating unit of each of said tray.
 3. Adisc cartridge according to claim 2, wherein: said slide guide has aguide rail and a fitting unit, said guide rail is disposed on a bottomsurface of each of said trays, and is configured by a grooved concaveportion extended in a direction, in which said trays are taken in andout, from a front end side of said trays to a back end side, and saidfitting unit is disposed on a top surface of a tray supporter providedin said case, and is configured by a convex portion to be inserted intosaid grooved concave portion.
 4. A disc cartridge according to claim 3,wherein: said concave portion has at an end thereof, a divergentlytapered convex portion introduction guide, and has at a center thereof,a notch hole in which a ligulate convex portion formed on said case isput when said trays are pulled out of said case by a predeterminedamount.
 5. A disc recording and/or reproducing apparatus comprising: adisc cartridge provided with a plurality of trays, each of which canhold a disc, and a case assembled so as to enable said trays to be takenin and out, wherein an operating unit disposed in each of said trays isdrawn or pressed to accordingly take said trays in and out; and arecording and/or reproducing unit, which is arranged on a side of saiddisc cartridge, for pulling said trays out of said disc cartridge andfor recording on and/or reproducing from the disc held by each of saidtrays, wherein each of said disc cartridge and said recording and/orreproducing unit has a slide guide at a position near said operatingunit of each of said tray, with respect to a direction in which saidtrays are taken in and out.
 6. A disc recording and/or reproducingapparatus according to claim 5, wherein: said slide guide of said disccartridge is composed of a grooved concave portion, which is disposed ona bottom surface of each of said tray and extended in a direction, inwhich said trays are taken in and out, from a front end side of saidtrays to a back end side; and a ligulate convex portion which is formedon a top surface of a tray supporter disposed in said case and isinserted into said grooved convex portion, and said slide guide of saidrecording and/or reproducing unit is composed of a convex portion to beinserted into a grooved concave portion of one of said trays which istaken into a side of said recording and/or reproducing unit from saiddisc cartridge.
 7. A disc recording and/or reproducing apparatusaccording to claim 6, wherein said grooved concave portion on saidbottom surface of each of said trays has a tapered convex portioninsertion guide for guiding an insertion of said convex portion, at anend of a tray front end side.
 8. A disc recording and/or reproducingapparatus according to claim 6, wherein said grooved concave portion onsaid bottom surface of each of said trays has a notch in which saidconvex portion is put, when said trays of said disc cartridge are pulledinto said disc recording and/or reproducing unit by a predeterminedamount.